Clinic-Diarrhea

Question 1

diarrhea symptoms vary dramatically, but diarrhea as a diagnostic SIGN is defined as?

Answer 1

stool weight >150-200 grams per 24 hours

Question 2

chronic diarrhea lasts more than ____ weeks and is (more/less) likely to be infectious in etiology

Answer 2

3; less

Question 3

acute diarrhea is usually caused by _______ and lasts less than?

Answer 3

self-limiting infection; 2-3 weeks

Question 4

half of the episodes of infectious diarrhea in the US are due to?

Answer 4

epidemics with contaminated food or water

Question 5

major bacterial causes of infectious diarrhea

Answer 5

salmonella, shigella, campy, e coli, c diff

Question 6

major viral causes of infectious diarrhea

Answer 6

noravirus, rotavirus, adenovirus, astrovirus

Question 7

major protozoan causes of infectious diarrhea

Answer 7

cryptosporidium, giardia, cyclospora, entamoeba

Question 8

mechanism of infectious diarrhea

Answer 8

direct tissue destruction OR pre-formed toxin mediates secretion

Question 9

most cases of acute infectious diarrhea are (bacterial/viral/protozoa)

Answer 9

viral

Question 10

if sx of food borne illness present within 6 hours then it must be?

Answer 10

preformed toxin (staph, bacillus)

Question 11

sx that begin more than 16 hours after infection are ____

Answer 11

viral or bacterial (direct tissue destruction)

Question 12

incubation of 8-72 hours is common with ___toxins

Answer 12

cyto- or enterotoxins (ETEC, cholera) = fluid secretion from cells

Question 13

presentation of bacterial enteritis

Answer 13

diarrhea, volume depletion, N/V, fever

Question 14

bacterial enteritis that presents with distended, silent bowel may be?

Answer 14

toxic megacolon

Question 15

warning signs that warrant testing of infectious diarrhea

Answer 15

systemic toxicity, severe pain, dehydration, bloody stools, >24 hours of sx

Question 16

a sigmoidoscopy should be obtained only if sx last for ____

Answer 16

several days

Question 17

name 5 categories of chronic diarrhea

Answer 17

osmotic, fatty, secretory, inflammatory, motility (IBS)

Question 18

pathophysiology of osmotic diarrhea

Answer 18

osmotic load in intestine results in retention of water in the lumen (i.e. sorbitol, non-digestive foods)

Question 19

pathophysiology of secretory diarrhea

Answer 19

excess secretion of electrolytes and water into the intestinal lumen

Question 20

pathophysiology of inflammatory diarrhea

Answer 20

exudation of fluid and protein from intestinal mucosa

Question 21

pathophysiology of motility-related diarrhea

Answer 21

rapid transit through the colon (i.e. caffeine)

Question 22

an avg of ___ liters a day are delivered to the GI tract, of which only ___ liters are consumed

Answer 22

9; 2

Question 23

the majority of water is absorbed in the (small/large) intestine

Answer 23

small

Question 24

bacterial enteritis that presents with distended, silent bowel may be?

Answer 24

toxic megacolon

Question 25

bacterial enteritis infecting the _____ produces large volume diarrhea without tenesmus

Answer 25

small intestine

Question 26

bacterial enteritis affecting the _____ produces frequent, small volume, bloody diarrhea

Answer 26

large intestine

Question 27

steatorrhea is a subset of what category of diarrhea?

Answer 27

osmotic/malabsorptive

Question 28

in osmotic diarrhea, ____ do not account for all of the water secreted in stool

Answer 28

electrolytes

Question 29

osmotic diarrhea is due to one of these two major causes

Answer 29

mucosal disease (damage to bowl = malabsorption); osmotic agents in lumen

Question 30

name three mucosal diseases of the small intestine that cause osmotic diarrhea

Answer 30

celiac, tropical sprue, whipple's disease

Question 31

name 2 mucosal diseases of the colon that cause osmotic diarrhea

Answer 31

IBD, infections

Question 32

name two causes of increased osmotic agents in the lumen

Answer 32

malabsorption or exogenous agents

Question 33

name two causes of malabsorption leading to osmotic diarrhea

Answer 33

pancreatic insufficiency (enzymes can't break down food) or small bowel bacterial overgrowth

Question 34

name exogenous agents that cause osmotic diarrhea

Answer 34

laxative, sorbitol, fructose/lactose in pts with specific enzyme deficiency

Question 35

how severe must pancreatic insufficiency be in order to cause steatorrhea?

Answer 35

SEVERE, greater than 90% decrease in secretions

Question 36

name 5 causes of pancreatic insufficiency

Answer 36

chronic alcoholism pancreatitis, CF, pancreatic resection, pancreatic cancer in certain locations, somatostatinoma

Question 37

how to dx pancreatic insufficiency

Answer 37

stool studies show fat, decreased fat soluble vitamins (DAKE)

Question 38

what causes bacterial overgrowth in the small bowel

Answer 38

decreased transit time due to motility disorders, diverticulae, strictures, diabetes

Question 39

dx of bacterial overgrowth

Answer 39

small bowel follow-through, hydrogen breath test (use sucrose), empiric abx trial

Question 40

osmotic diarrhea _____ with fasting while secretory diarrhea ____

Answer 40

goes away/decreases, continues

Question 41

secretory diarrhea is due to?

Answer 41

stimulated secretion of intestinal cells

Question 42

secretory diarrhea is associated with what major sx and major lab finding

Answer 42

substantially elevated stool volumes; hypokalemia

Question 43

what channel is involved in secretory diarrhea? What ion is secreted?

Answer 43

CFTR, increase in cAMP leads to opening of CFTR and increased chloride secretion

Question 44

MoA of cholera toxin

Answer 44

B subunit binds, A subunit enters enterocyte and catalyzes persistent activation of adenylate cyclase (constitutive opening of CFTR)

Question 45

name 4 bacterial toxins that cause secretory diarrhea

Answer 45

vibrio cholerae, c diff, e coli, shigella

Question 46

____ tumors (name 3) can also cause increased secretion

Answer 46

endocrine (VIPoma, gastrinoma, carcinoid)

Question 47

inflammatory cell products can cause what type of diarrhea

Answer 47

secretory

Question 48

plasma osmolarity is normally

Answer 48

290

Question 49

equation for the stool osmotic gap

Answer 49

290 - 2(stool Na + stool K)

Question 50

osmotic diarrhea is defined by an osmotic gap greater than ____ which stool Na less than ___

Answer 50

100; 60

Question 51

secretory diarrhea tends to have a ___ osmotic gap and a ___ sodium (Na)

Answer 51

low; high

Question 52

in inflammatory diarrhea, _____ leads to increased permeability, while _______ lead to stimulated secretion and inhibited absorption

Answer 52

mucosal destruction; cytokines

Question 53

4 features associated with inflammatory diarrhea

Answer 53

WBCs in stool, blood in stool, fever, tenesmus

Question 54

what are the two major causes of inflammatory diarrhea

Answer 54

IBD, infections

Question 55

name 4 infections that cause destruction and thus inflammatory diarrhea

Answer 55

EIEC, shigella, salmonella, c diff

Question 56

c diff is (aerobic/anaerobic) and gram (positive/negative)

Answer 56

anaerobic, gram positive

Question 57

pathophysiology of c diff

Answer 57

2 primary toxins leads to increased epithelial permeability, cytokine secretion, infiltration of inflammatory cells, and cell death

Question 58

dx of c diff

Answer 58

toxin assay, PCR, endoscopy (pseudomembranous colitis)

Question 59

blood workup for diarrhea

Answer 59

CBC, ESR, electrolytes

Question 60

stool studies for diarrhea

Answer 60

c diff toxin, bacterial screen, ova/parasites, electrolytes, WBCs, lactoferrin/calprotectin

Question 61

what do lactoferrin/calprotectin detect?

Answer 61

inflammation (IBD?); neutrophil derived proteins measured with ELISA

Question 62

this test looks for fat in the stool

Answer 62

sudan stain (looks orange-brown)

Question 63

this tests for bacterial overgrowth and/or lactase deficiency

Answer 63

breath hydrogen tests

Question 64

special media are required to detect?

Answer 64

aeromonas and pleisiomonas (from well water, fresh ponds)

Question 65

for what two diseases might you do a capsule endoscopy?

Answer 65

Crohn's dz, celiac dz (small bowel processes)

Question 66

thick folds on capsule endoscopy suggest?

Answer 66

celiac dz

Question 67

the immune response produced in celiac dz is (innate/adaptive/both)

Answer 67

both

Question 68

anti-endomesial Ab, Anti TTG test for..

Answer 68

celiac dz